Heart and Vascular Wall as Targets for Tissue Converting Enzyme Inhibition

Components of the renin-angiotensin system (RAS) have been described in different tissues including the heart and vascular wall. Recently angiotensin I (ANG I) and ANG II were demonstrated in the heart and the aorta of rhesus monkeys and rabbits, and pharmacological interference with the converting enzyme (CE) inhibitor ramipril reduced CE activity and ANG II generation in these tissues, supporting the concept of intrinsic local RAS (1, 2). To investigate the significance of this local CE inhibition in heart and vascular wall, studies were performed in isolated working rat hearts and in isolated arterial preparations in the presence and absence of an intact endothelium.